Oscillatory hammer



H. D. GREENBERG OSC ILLATORY HAMMER Aug. 31, 1943.

Filed June l, 1942 flql. 24 :26 2:9 27 26 @si I ,f if 1 l! u J2 f5 J9 22 23 I .Z 21 I ci l WW al `Patented Aug. 1943 f2,32s,v27`oif T.` T e os(JILLiifroa'YHAMMi`4 "im l Harry Daniel Greenberg, NewjYork, NiY. T e f Application .rune 1,V 1942, Serial Nefiisat A `tamarins T(o1. `74"-576)4 e My invention relates to improvements in oscill latory devices andhammers, the motivepower being previded for by a rotating shaft.` e e Theprimary object of my invention is 4to providesuch a device with adiflerential `stroketravely to permit blows of different intensities. k

Another object is to provide aUdifferent stroke travel by a reversal of theTrotation of the driving shaft. l a T T T Still another obect isl toprovide such a device in whichthe line ofthe hammerI travel and the direction of the blow,l is inthe same Taxis and parallel to` theY axis of the motive` drive with a viewto minimizing` lateral and centrifugal vibration usually foundin devices of this `charas `,at|9. to receive aca'p 20 centrally apertured at 2 IT as hereinafter described.T

The oscillatory producing mechanism I8 cony sistsTnof` the collar provided with the periphacter employing eccentric drives and other unbalanced means. a l, 1

Other objects of my inventionare to provide a device of the foregoing character that` may be readily attached to dental-engine handpieces or contra-angles for Various types of dental uses; to provide a' device which is simple in construction and assembly, and which may be inexpensively manufactured.

I accomplish these and other objects and Tob- `tain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated which:v a

Fig. 1 is a partially sectional view of my device wherein the hammer travel is ina direction normal to the axis shaft. e l a Fig. 2 is an exploded viewiof the elementsof my device that produce the oscillatory effect. Fig. 3 is a sectional view loi" a modification of my device wherein thehammer travel is in the of rotation"V of the main drive same direction as theaxis of rotation of the main l drive shaft.

Fig. 4 is apersp'ective outside view of my def, `vice employed in a contra-.angle dental hand piece. a t e Referring more particularly to the drawing,

reference numeral I0 designates, in Fig. 1, a cas-` T ing wherein is journalled a'drive shaft II. One

end of the shaft II carries a bevelgear I2, `secured thereto by a pin I3. The endof the casing Iltis threaded "and engages at I4 the head `I5.` The Vhead terminatesina tubular transversely extending casing I6 provided with a recess II to `receive the oscillatory producing mechanism I8, illustrated in the exploded view in Fig. 2. The mouth of the recess I1 is threaded,

in the .accompanying drawing, in`

T l. mined height.

e erally formed bevel gear 3| which engages the corresponding bevel gear I2 driven by shaft The collar ,30 is hollow as at 32, and provided; with a flattenedminner portion 33 at one end thereof,VA and Ta. peripherally formed ,shoulder 34a.l

Into the"hol1ow` end of the` collar 30 is inserted the driving cam 40,.Whichfcomprises a cylin-l drically `shaped `shaft, 4|,` longitudinally flattened at one end as .at 42, for engagement with the flattened inner portion 33 of the collar 30, and, thereby locked to the collar and forced tof rotate vWithlit. A groove 43 is peripherally` formed. around the cylindrical wall of the driving cam 40, for the purpose of rotatably and removably` locking it to the head I6 if desired, as will be hereinafter described. The driving cam is providedwith a spirally formed cam sur` face V44,-normal to the axis `of rotation with a cam drop in the spiral surface of `predeter- An intermediate cam `shaft`5|l `is similarly provided with a` cam surface 5|, in juxtaposition to cam surface, and provided similarly with a cam; drop 52desig`ned to interlock with cam 2 drop 45. Atlthelremaining endV of intermediate camyshaft v5I), an oppositely `formed cam surface 53is positioned with a camdrop 54 of` predetermined height. e l a' a 4A final 4driven cam yshaft 60 is provided with 1 a cam surface 6I and a `cam drop 62 in juxtaposition to cam surface 53 and cam drop 54 of' the a intermediate'cam shaft `5Il.`4`` e e A pin `6.3 is driven through driven cam shaft Whichis designed to fit into the diametrically formed slotsy22 in the inside of cap 20 with'shaft 64 extendingthrough aperture 2|. Thus the shaft 6|) is prevented from rotating withf respect to thecap 20, but may longitudinally oscillate inthe slotsT 22 thereof. The remaining end ofTdriven Tcam shaftTB may vbe threadedly frecessed as at 65 to4 accommodatea suitablyfaced tool 10 which in this instance itis desiredto be longitudinally oscillated. vj 1T n ,a

-A vthrust bearing 2,4 may be inserted into the e recessTTl'I ofthe headIG, `seating itself atv the extreme end thereof, 'adjacent the shoulder 3 4 a 'fwjcbur 3o.; Theariving `cam shaft aoTprotmdes through aperture 25 in head` I 6',Tand.may:be rotatably lo'cked by the lever 26 mounted with a'slot 28 in head I6, whichlever26fis pivoted at set screw 21, and is provided with a cut-out 29a,for engaging the slot 43 (see Fig. 4) I The oscillatory producing mechanism I8 is assembled as a unit into the recess I'I of head I6 through the threaded end I9, and comprises the collar 30, the driving cam 40 inserted into collar 30 from the lowerend 35 thereof, the intermediate cam 50 next inserted into Tend' 35, and the driven cam 6D following cam 50 into the collar. A spring 23 may be inserted into the recess of the cap 20 to keepv the'l cam surfaces into interengagement. y v

The cap 20 is then threaded into the mouth of recess I'I, and the casing I0 with shaft Il, and bevel gear I2 threaded at I4 to positionv` at the end of head I5.

The lever 26 is then pivoted from the position indicated in Fig. 4 to the closed position of Fig. 1,

rotatably locking the driving cam 40', and the'device is ready for operation. K.

The shaft II and driving bevel gear I2 rotates the meshed bevel gear 3l; causing collar 3i)- to rotate carrying driving camy v4I) with it. If the cam 'isrotated in thel direction of arrow yAof Fig. 2 it engages' cam drop52 of intermediate `cam 50, causing the intermediate cam 50 to rotate with it. The cam surface 53 is` oppositely positioned so that cam surface 53 propels cam shaft 5U the vdistance of cam drop 54, thereby causing the driven clin shaft shaft I I in one direction will cause an oscillation over a distance equal to the height of cam drop 54 or 62, and upon reversal of the shaft rotation, the cams B9 and 5I! will oscillate asa unit over a distance equal to theheig'ht of cam drop 52 or 45. By proper designr of the cam drops, the distance of oscillation may be selectively changed bya simple reversal of shaft rotation.v

it should be noted that theilever 25 is shown because it is normally used in dental contraangles to lock a dental burr 10a, into rotatable position. The contra-angle of Fig. Llis' adapted to receive the'oscillatory producing mechanism of Fig. 2, without any change except for the recsss in the cap 2U for'pin 63. l f

f a contra-angle device is desired with no need for accommodation to the present type of dental instrument, the headmay be made closed at this point, eliminating lever 26, aperture 25, slot 43 and 'setscrew 21." v i In Fig. 3, a device is shown in which the hammer travel is in the samev direction as theaxis of rotation of the main driving shaft. v While the three piece cam shaft arrangement may be used, shown as an, su and 6u in Fig. 2, the parte may be further Simplified by employing a single set of cam faces, where reversal of ythe drlve shaft is undesirable, unnecessary or'not available.

Thus the outsidec'asing 80 houses* the main drive shaft I, which terminates in the drive cam 82 integral therewith. This is journalled in the neck 83 of thecasing, and is maintained in position by the inner casing shoulder 84, and

k69 to' oscillatefor vibrate within collar 3i?, the pin 63 riding longitudinally in slots 22 of shown in Fig. 4, i

by the ears or pin 85 on the shaft SI. A spirally formed cam face 86, provided with a cam drop 81, is juxtaposed to cam surface 83 with a corresponding cam drop, forming part of driven cam shaft 89. A suitably faced tool 99 threadedly engages the recess 9I in the driven cam 89, which is providedwith a longitudinally formed slot 92 into which is keyed a threaded set screw 93 mounted in the threaded aperture 94 of the casing neck 33.

vWhen the shaft is rotated in the direction of the arrow, the driving cam 82 will cause driven cam 89 to oscillate the distance of the cam drop 81. The return spring 23 of Fig. l may be omitted A for the pressure of the tool on the hammered v.surface may be relied on to cause the driven cam to ride the cam surfaces.

Furthermore, by manually 'con-trolling the degree of pressure, the

. amount of hammer travel can be controlled.

In 'the various modifications, the' forward movement of the tool is at all times under the power of the main drive.r

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, thel'same being merely illustrative, and that the invention may be carried out inI other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention` arel attained, and new vresults accomplished, as it is obvious that the particular embodiments herein shown and described yare onlysome of the many that can be employed to attain these objects and accomplish these results. f

What I claim and desire to secure by Letters i Patent, is as follows:

l. An oscillatory device comprising a supporting member; a rotating driving cam unit'journalled therein, havinga transversely faced, spirally formed cam surface with a circumferential cam drop of predetermined height; a driven cam journalled in said supporting member, provided with a cam surface operable by the cam surface of the driving cam unit, for propelling the driven cam and the driving cam unit away from each other a distance equal to the height of the driving cam drop; a tool actuated by said driven cam; locking means for preventing the rotation of said tool when the driving cam is rotating with respect to the driven cam; and means automatically operable for permitting the driven cam and the driving cam to rotate together as a unit when the direction of rotation of the driving cam is reversed; said driven caminormally pressed against said driven cam unit during the rotation ing member; a rotating driving cam unit journalled therein, having artransversely'i'aced, spirally formed cam surface with a circumferential cam drop of predetermined height; a driven cam journalled in said supporting member, provided with acam surface operable by the cam surface of the driving cam unit, for propelling the driven cam and lthe driving cam unit away from each other a distance equal to the height of the driving cam drop; a tool actuated by said driven cam; locking means for preventing the rotation of said tool when the driving cam is'rotating with respect to the driven cam; said driving cam unit composed of two sections, each provided with spirally formed cam surfaces and corresponding cam drops adjacent each other, whereby the two sections will interlock and operate as a unitary driving `cam against the driven cam when the driving cam unit is rotated in one direction and when the direction of rotation is reversed,` the section of the driving cam unit adjacent the driven'cam will interlock with the driven cam and `cause the two sections to be propelled away from each other a distance equal to the height of their respective `cam drops; said driven cam normally pressed against said driving cam unit during the rotation ofthe driving cam unit.

31` In a hand piece having a driving shaft terminating in an integrally attached bevel gear,

l and a hollow collar provided with a peripherally formed bevel gear having its axis at right angles to the axis of the driving shaft and in engagemerit with the bevel gear at the end thereof; an oscillating mechanism comprising a three section shaft for insertion within the hollow collar, one end section of which is integrally connected to the collar, and having the adjacent faces of said .pieces provided with oppositely formed spirally shaped cam surfaces and cam drops; a toolactuated by the remaining end of said pieces; locking means for preventingrotation of said tool; one

set of adjacent cam surfaces interlocking and j operating as a unitary unit causing the tool to be propelled a distance equal to the height of the l cam drop of the remaining cam faces-when the collar is rotated in one direction, and when the direction of rotation is reversed, the remaining set of adjacent cam faces will interlock and cause the tool to be propelled a distance equal to the 

